The Thompson plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.
Mostly sunny
Partly cloudy; warmer
Mostly sunny
Mostly sunny
Partly cloudy
Partly cloudy
Showers likely
Thompson’s center stands about 1,280 ft above sea level. Within three miles the land runs from 1,210 ft to 1,290 ft, a difference of 80 ft: gently rolling country. The highest named summit within 15 miles is Pilot Knob, about 1,440 ft, 14 miles southeast.
The section below crosses 4 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Shale, dolostone. Age: Late Ordovician, 447 to 454 million years old. About 13 mi of the line.
Limestone, dolostone. Age: Middle Devonian to Late Devonian, 374 to 388 million years old. About 6 mi of the line.
Dolostone, limestone. Age: Late Ordovician, 447 to 459 million years old. About 4 mi of the line.
Sandstone, shale. Age: Early Cretaceous to Late Cretaceous, 94 to 113 million years old. About 1 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale.
Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.
A raindrop that lands in Thompson reaches the Gulf of America by way of Little Buffalo Creek, the Des Moines and the Mississippi: about 1,760 river miles.
Lakes on the way: Roberts Creek and Big Creek Pounding Area.
1,330 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Thompson; river miles along the main stem, rounded.
